The transport group behind nearly a third of UK rail journeys suffered a profits fall today as the double-dip recession hit demand for one of its key commuter lines.

Go-Ahead said operating profits at its rail arm fell 17 per cent to £40m in the year to June 30, with its Southern franchise, which connects Brighton and much of Sussex with London, seeing revenues at the end of the period 2 per cent weaker than it forecast when it bid for the franchise in 2009.

The Newcastle-based firm, which also runs Southeastern and London Midland, raised the possibility that Southern could receive revenue support from the Government in a year's time, with the economy expected to continue to weigh on its performance.

Group pre-tax profits fell 3.4 per cent to £94.2m, overshadowing record profits at its bus division outside London, which enjoyed its highest ever passenger numbers.